Analytical Gradients for Projection-Based Wavefunction-in-DFT Embedding
Abstract
Projection-based embedding provides a simple, robust, and accurate approach for describing a small part of a chemical system at the level of a correlated wavefunction (WF) method, while the remainder of the system is described at the level of density functional theory (DFT). Here, we present the derivation, implementation, and numerical demonstration of analytical nuclear gradients for projection-based wavefunction-in-density functional theory (WF-in-DFT) embedding. The gradients are formulated in the Lagrangian framework to enforce orthogonality, localization, and Brillouin constraints on the molecular orbitals. An important aspect of the gradient theory is that WF contributions to the total WF-in-DFT gradient can be simply evaluated using existing WF gradient implementations without modification. Another simplifying aspect is that Kohn-Sham (KS) DFT contributions to the projection-based embedding gradient do not require knowledge of the WF calculation beyond the relaxed WF density. Projection-based WF-in-DFT embedding gradients are thus easily generalized to any combination of WF and KS-DFT methods. We provide a numerical demonstration of the method for several applications, including a calculation of a minimum energy pathway for a hydride transfer in a cobalt-based molecular catalyst using the nudged-elastic-band method at the coupled-cluster single double-in-DFT level of theory, which reveals large differences from the transition state geometry predicted using DFT.
Additional Information
© 2019 Published under license by AIP Publishing. Submitted: 13 May 2019; Accepted: 3 July 2019; Published Online: 9 August 2019. We thank Matthew Welborn for helpful discussions. This material is based on the work supported by the U.S. Army Research Laboratory under Grant No. W911NF-12-2-0023 (S.J.R.L.). S.J.R.L. thanks the Caltech Resnick Sustainability Institute for a graduate fellowship. T.F.M. and F.R.M. acknowledge joint support from the DOE (Award No. DEFOA-0001912), and F.R.M. acknowledges support from the Engineering and Physical Sciences Research Council for funding (No. EP/M013111/1).Attached Files
Published - 1.5109882.pdf
Submitted - 1903.05830.pdf
Supplemental Material - Supp_material.zip
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Additional details
- Eprint ID
- 95433
- Resolver ID
- CaltechAUTHORS:20190513-111036074
- Army Research Office (ARO)
- W911NF-12-2-0023
- Resnick Sustainability Institute
- Department of Energy (DOE)
- DE-FOA-0001912
- Engineering and Physical Sciences Research Council (EPSRC)
- EP/M013111/1
- Created
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2019-05-13Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field
- Caltech groups
- JCAP, Resnick Sustainability Institute